What Are the Most Common Causes of Hand Pain?

In Chinese, "pain" refers to residual pain; "pain" refers to the nociceptive feeling inside the patient's body. The so-called pain in modern medicine is a complex physiological and psychological activity and is one of the most common symptoms in the clinic. It includes painful sensations caused by nociceptive stimuli on the body, and the body's painful responses to nociceptive stimuli (somatic and / or visceral vegetative responses, often accompanied by strong emotional color). Pain can be used as a warning that the body is harmed, causing a series of defensive protective reactions for the body. But on the other hand, pain has its limitations as an alarm (for example, when it is too late for cancer, etc.). And some long-term severe pain has become an intolerable torture for the body. Therefore, analgesia is an important task for medical workers.

pain

(Physiological and psychological activities)

Mechanical stimuli such as cutting and stick striking, current, high temperature and strong

The nature of pain is sometimes extremely difficult to describe. One can usually indicate the location and extent of the pain, but it is more difficult to describe it accurately

Involving pain diagnosis and treatment projects based on development status

1. Acute pain: pain in soft tissues and joints, pain after surgery, obstetric pain, acute shingles

Every advancement in the study of pain theory and mechanism has brought new strategies and measures to the prevention and treatment of pain. Any measures that reduce the introduction of fine fibers and / or strengthen the introduction of fibers can help treat or relieve pain. In addition to using traditional local anesthetics to block or block the fine fiber activity of the afferent pathway, physical therapy such as massage, massage, heat therapy, and electrotherapy can also relieve pain. Acupuncture and mild electrical stimulation of nerves have been widely used in the treatment of pain, especially chronic pain. In the treatment of drugs, disinhibition

Cancer pain patients have traditionally been divided into cancerous pain, non-cancerous pain, or both. The treatment of these patients is mainly based on different tumors, different anatomical locations, and familiar characteristics of typical symptoms. The complexity and treatment of cancer pain. Burst pain is defined as a sudden onset of pain in a patient during effective analgesic treatment. Burst pain can be classified as

1. According to pathological characteristics, pain can be divided into nociceptive pain and neuropathic pain (or two types of mixed pain).

Nociceptive pain is the response of intact nociceptors to harmful stimuli. Perception of pain is related to tissue damage. Under normal circumstances, pain impulses are produced by nerve endings,

In the past, there was not enough understanding of the differences between acute pain and chronic pain. Now there is a clear understanding of the differences in the etiology, pathogenesis, pathophysiology, symptomology, diagnosis and treatment of the two types of pain. Pain is a symptom of the disease, and chronic pain is a disease in itself.

The basic neural conduction process of pain can be divided into 4 steps. Nociceptive sensory (transduction), primary afferent fibers, spinal dorsal horn, spinal cord-thalamus bundles and other ascending bundles of transmission (transmission), cortical and limbic system of pain (interpretation), downward control and neural media Modulation of pain.

(A) the mechanism of acute pain

Acute pain is nociceptive pain. The mechanism of nociceptive pain is the basic nerve conduction process of pain formation. After the body is stimulated by physical, chemical or inflammatory stimuli, it produces acute pain signals, which are sensed through nerve conduction and brain analysis.

1.Pain sensory

Skin, body (muscles, tendons, joints, periosteum, and bones), small blood vessels and connective tissue next to capillaries, and visceral nerve endings are peripheral nociceptors of pain.

Body surface stimuli transmit pain through skin temperature and mechanoreceptors. Visceral nociceptors sense contraction, swelling, or ischemic stimuli of cavity organs, and pain in the motor system is sensed by somatic nociceptors.

2.Upward transmission of pain

(1) Afferent afferent nerve fibers: The primary afferent axons that conduct pain signals are myelinated A fibers and unmyelinated C fibers, and their neuronal bodies are located in the dorsal root ganglia of the spinal cord.

(2) Transmission of pain signals in the spinal cord: The spinal cord is the primary center of pain signal processing. The signals of nociceptive stimuli are introduced into the dorsal horn of the spinal cord from the primary afferent fibers. After preliminary integration, they act on the ventral horn motor cells on the one hand, causing local defensive reflexes, and on the other hand they continue to pass upward.

(3) pain signals are transmitted from the spinal cord into the brain

The upward pathways of pain signals transmitted by different parts of the body on the spinal cord are divided into: the pain pathways of the trunk and limbs, the pain pathways of the head and face, and the visceral pain pathways.

The pain pathways of the trunk and extremities include: a new spine-thalamus bundle, which transmits information that can be projected to the upper 2/3 of the central posterior gyrus (region 3.1.2) through the specific sensory nucleus of the thalamus, with Ability to accurately locate and analyze; the old ridge-mound bundle or ridge-mesh-mound bundle, most of the fibers are stopped in the medial reticular structure of the brainstem on the way up, and then transmitted to the thalamus through multi-stage transformation of intermediate neurons. Structures such as the medial nucleus group of the medullary plate are closely related to the intense emotional response and visceral activity accompanied by pain.

Head and Facial Pain Pathway: The head and facial pain sensation of the first-level neuron cell body is located in the trigeminal nerve semilunar ganglion, and its axon terminates in the trigeminal nerve sensory nucleus and the trigeminal spinal nucleus. From this change, the fibers were sent across the contralateral side to form the trigeminal system, which was projected to the ventromedial nucleus (VPM) of the thalamus. Fibers from the VPM are projected through the inner occipital occipital to the lower third of the central posterior gyrus (area 3.1.2).

Visceral pain pathway: The afferent pathways of visceral pain are scattered, that is, the afferent fibers of an organ can enter the center through several segments of the spinal cord, and a spinal nerve can contain afferent fibers of several organs, so visceral pain It is often diffuse and the positioning is not accurate enough.

(4) Receptors involved in pain signaling

Many receptors are involved in the transmission of pain signals in the pathway. Among them, the opioid receptor (-opioid receptor, -opioid receptor and -opioid receptor) are the most important receptors in pain signal transmission and analgesia. In the past, these three opioid receptors were mainly distributed in the central nervous system such as the spinal dorsal horn and the brain. Recent studies have found that the three opioid receptors are distributed in the entire nervous system, including the peripheral nervous system and intermediate neurons.

3.Pain integration in the cortex and limbic system

The spinal cord thalamic bundle enters the thalamus to form secondary neurons and emit fibers: to the somatosensory part of the white matter; connected to the reticular structure and thalamic nucleus, so breathing and circulation will be affected when pain is felt; extended to the limbic system And cingulate gyrus, causing painful emotional changes; connected to the pituitary gland, causing endocrine changes; connected to the ascending reticular activation system, affecting attention and alertness. The thalamus is not only the most important transmission center before various somatosensory information enters the cerebral cortex, but also the important integration center.

Some structures in the limbic system may be related to the emotional component of pain. Cerebral cortex This is an important part of a variety of sensory signals entering the realm of consciousness to form sensations. The main role of the cerebral cortex in the integration of pain is to distinguish the pain.

4. Downward pain regulation

In the nervous system, there is not only a pain signal transmission system, but also a pain signal regulation system. The pain signal regulation system is an endogenous pain modulation system. This system can not only sense and distinguish pain signals, but also produce a strong self-pain relief effect.

(1) Spinal cord level regulation: There are a large number of endogenous opioid peptides (enkephalins and dynorphins), interneurons, and various opioid receptors involved in the dorsal horn pain signal regulation in the glial region of the spinal dorsal horn.

(2) Regulation of brain level: The important structure of endogenous pain modulation is located in the descending analgesia system of the brain. The midbrain aqueduct gray matter (PAG) is an important structure that plays a central role in the analgesia system of endogenous pain modulation.

(3) Downward pain facilitation system: by reducing the pain threshold (sensitization) to improve the body's ability to respond to nociceptive stimuli, it also makes patients show high sensitivity to pain.

(4) Regulators of the downward pain regulation system: Opioid peptide is the most important activation and regulator in the downward pain regulation system. The analgesic potential of the human body is largely affected by the release of endogenous opioid peptides and the downward pain regulation it participates in.

The pain control system is also involved in the analgesic mechanism of painkillers. Exogenous opioids also exert analgesic effects by activating opioid receptors in the brain, spinal dorsal horn, and ganglia. Tricyclic antidepressants play an auxiliary analgesic effect by selectively inhibiting the reuptake of the neurotransmitters norepinephrine and serotonin by nerve endings.

(B) the mechanism of chronic pain

To be added